/*
 * Copyright � 2002-2011 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

using System.Data;
using Spring.Objects.Factory;
using Spring.Util;

namespace Spring.Data.Common;

/// <summary>
/// IDbProvider implementation that delegates all calls to a given target
/// IDbProvider
/// </summary>
/// <author>Mark Pollack</author>
public class DelegatingDbProvider : IDbProvider, IInitializingObject
{
    private IDbProvider targetDbProvider;

    /// <summary>
    /// Initializes a new instance of the <see cref="DelegatingDbProvider"/> class.
    /// </summary>
    public DelegatingDbProvider()
    {
    }

    /// <summary>
    /// Initializes a new instance of the <see cref="DelegatingDbProvider"/> class.
    /// </summary>
    /// <param name="targetDbProvider">The target db provider.</param>
    public DelegatingDbProvider(IDbProvider targetDbProvider)
    {
        this.targetDbProvider = targetDbProvider;
    }

    /// <summary>
    /// Gets or sets the target IDbProvider that this IDbProvider should delegate to
    /// </summary>
    /// <value>The target db provider.</value>
    public IDbProvider TargetDbProvider
    {
        get { return targetDbProvider; }
        set
        {
            AssertUtils.ArgumentNotNull(value, "TargetDbProvider");
            targetDbProvider = value;
        }
    }

    /// <summary>
    /// Returns a new command object for executing SQL statments/Stored Procedures
    /// against the database.
    /// </summary>
    /// <returns>An new <see cref="IDbCommand"/></returns>
    public virtual IDbCommand CreateCommand()
    {
        return TargetDbProvider.CreateCommand();
    }

    /// <summary>
    /// Returns a new instance of the providers CommandBuilder class.
    /// </summary>
    /// <remarks>In .NET 1.1 there was no common base class or interface
    /// for command builders, hence the return signature is object to
    /// be portable (but more loosely typed) across .NET 1.1/2.0</remarks>
    /// <returns>A new Command Builder</returns>
    public virtual object CreateCommandBuilder()
    {
        return TargetDbProvider.CreateCommandBuilder();
    }

    /// <summary>
    /// Returns a new connection object to communicate with the database.
    /// </summary>
    /// <returns>A new <see cref="IDbConnection"/></returns>
    public virtual IDbConnection CreateConnection()
    {
        return TargetDbProvider.CreateConnection();
    }

    /// <summary>
    /// Returns a new adapter objects for use with offline DataSets.
    /// </summary>
    /// <returns>A new <see cref="IDbDataAdapter"/></returns>
    public virtual IDbDataAdapter CreateDataAdapter()
    {
        return TargetDbProvider.CreateDataAdapter();
    }

    /// <summary>
    /// Returns a new parameter object for binding values to parameter
    /// placeholders in SQL statements or Stored Procedure variables.
    /// </summary>
    /// <returns>A new <see cref="IDbDataParameter"/></returns>
    public virtual IDbDataParameter CreateParameter()
    {
        return TargetDbProvider.CreateParameter();
    }

    /// <summary>
    /// Creates the name of the parameter in the format appropriate to use inside IDbCommand.CommandText.
    /// </summary>
    /// <remarks>In most cases this adds the parameter prefix to the name passed into this method.</remarks>
    /// <param name="name">The unformatted name of the parameter.</param>
    /// <returns>The parameter name formatted foran IDbCommand.CommandText.</returns>
    public virtual string CreateParameterName(string name)
    {
        return TargetDbProvider.CreateParameterName(name);
    }

    /// <summary>
    /// Creates the name ofthe parameter in the format appropriate for an IDataParameter, i.e. to be
    /// part of a IDataParameterCollection.
    /// </summary>
    /// <param name="name">The unformatted name of the parameter.</param>
    /// <returns>The parameter name formatted for an IDataParameter</returns>
    public virtual string CreateParameterNameForCollection(string name)
    {
        return TargetDbProvider.CreateParameterNameForCollection(name);
    }

    /// <summary>
    /// Return metadata information about the database provider
    /// </summary>
    public virtual IDbMetadata DbMetadata
    {
        get { return TargetDbProvider.DbMetadata; }
    }

    /// <summary>
    /// Connection string used to create connections.
    /// </summary>
    public virtual string ConnectionString
    {
        get { return TargetDbProvider.ConnectionString; }
        set { TargetDbProvider.ConnectionString = value; }
    }

    /// <summary>
    /// Extracts the provider specific error code as a string.
    /// </summary>
    /// <param name="e">The data access exception.</param>
    /// <returns>The provider specific error code</returns>
    public virtual string ExtractError(Exception e)
    {
        return TargetDbProvider.ExtractError(e);
    }

    /// <summary>
    /// Determines whether the provided exception is in fact related
    /// to database access.  This can be provider dependent in .NET 1.1 since
    /// there isn't a common base class for ADO.NET exceptions.
    /// </summary>
    /// <param name="e">The exception thrown when performing data access
    /// operations.</param>
    /// <returns>
    /// 	<c>true</c> if is a valid data access exception for the specified
    /// exception; otherwise, <c>false</c>.
    /// </returns>
    public virtual bool IsDataAccessException(Exception e)
    {
        return TargetDbProvider.IsDataAccessException(e);
    }

    /// <summary>
    /// Invoked by an <see cref="Spring.Objects.Factory.IObjectFactory"/>
    /// after it has injected all of an object's dependencies.
    /// </summary>
    /// <remarks>
    /// <p>
    /// This method allows the object instance to perform the kind of
    /// initialization only possible when all of it's dependencies have
    /// been injected (set), and to throw an appropriate exception in the
    /// event of misconfiguration.
    /// </p>
    /// <p>
    /// Please do consult the class level documentation for the
    /// <see cref="Spring.Objects.Factory.IObjectFactory"/> interface for a
    /// description of exactly <i>when</i> this method is invoked. In
    /// particular, it is worth noting that the
    /// <see cref="Spring.Objects.Factory.IObjectFactoryAware"/>
    /// and <see cref="Spring.Context.IApplicationContextAware"/>
    /// callbacks will have been invoked <i>prior</i> to this method being
    /// called.
    /// </p>
    /// </remarks>
    /// <exception cref="System.Exception">
    /// In the event of misconfiguration (such as the failure to set a
    /// required property) or if initialization fails.
    /// </exception>
    public virtual void AfterPropertiesSet()
    {
        if (TargetDbProvider == null)
        {
            throw new ArgumentNullException("Property 'TargetDbProvider' is required.");
        }
    }
}
